The plot thickens!
I was hoping that it was a standard AA job. I might be able to reseal it myself but it looks like a special seat that the small brass valve has, that is screwed into the end on the right.The double O ring part is just a slide on cylinder support and seal for the reg volume area, if that makes sense.
Simple design, which in my book is usually best if it does what its supposed to.I will have to have a dabble myself if I cannot find who made it.
Was hoping to find the maker as it would be easier to let the maker set it up and re seal.
Failing that I might have to turn the reg body down to retain the original firing valve spring, and fit another reg after it with a stand off.
I have had the cylinder re blued by Colin Malloy and it should look great when put back together.
Any more suggestions or information would be appreciated, and thanks for the comments.